1. Field of the Invention
This invention relates to a semisubmerged twin hull ship which cruises at high speed on wave sea, and in particular to an improvement in its longitudinal ship oscillating motion.
2. Description of the Related Art
Ship's high speed has so far been achieved by either a foil type or a surface effect type for small or medium-size ships, but for large-size ships high speed has so far not yet been realized due to a difficulty in controlling the ship oscillation particularly in the longitudinal direction on wave sea.
It is known that a ship provided with self-stability can hardly control its oscillation, in particular in the longitudinal direction, when the ship cruises in wave sea.
A fin control method of controlling longitudinal ship oscillations has recently been developed. However, no mention has ever been made to using the controlling effects of the fins besides designing the strut by taking into account the self-stability moment and the Munk's instability moment.
This invention aims at controlling ship's longitudinal oscillation by focusing attention on the ship's self-stability moment and the Munk's instability moment for a semisubmerged twin hull ship.